Extendable frame work vehicle

ABSTRACT

An extendable frame work vehicle offering enhanced versatility, safety and effectiveness. The vehicle includes an adjustable frame with front and rear portions that extend or retract with respect to each other. The front portion is supported by a first pair of wheels and said rear portion is supported by a second pair of wheels. Each wheel is independently driven and steered. The vehicle also includes an engine mounted on the rear portion of the frame. Incorporated into the vehicle is an electro-hydraulic assembly which enables extension and retraction of the adjustable frame. The assembly includes a sensor-responsive microprocessor controller, at least one hydraulic pump, at least one hydraulic drive motor, and at least one valve network.

CROSS-REFERENCED TO RELATED APPLICATIONS

This application is a divisional of application Ser. No. 11/890,332,filed Aug. 6, 2007, and claims priority from that application, which isalso deemed incorporated by reference in its entirety in thisapplication.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable

BACKGROUND OF THE INVENTION

I. Field of the Invention

This invention relates generally to extendable frame vehicles, and moreparticularly to extendable frame work vehicles capable of enhancedperformance of a variety of construction, landscaping, residential,agriculture and industrial tasks.

II. Related Art

In recent decades, construction equipment capabilities have increaseddramatically as have the variety of specialized machines and vehiclesthat are useful to persons performing jobs at various worksites. Tocomplete many projects, a variety of such specialized vehicles must bedelivered to a specific worksite on large trucks or trailers. Thesevehicles may include skid steer loaders, front end loaders, backhoes,rough terrain forklifts, or any of a large number of trucks and similardevices. Acquiring and transporting such a variety of equipment can bedifficult and costly. Further, mastering operation of the many steeringand control systems for these different vehicles is known to be anarduous task. It has been frequently recognized, for example, thatreducing the number of machines necessary for a particular job would beadvantageous. This is especially true when such reduction can be donewithout sacrificing capabilities of the various machines. A vehiclethen, which combines selected useful features of several former vehiclesand makes these features even more useful and versatile, would be highlydesired and valued by persons in this industry.

Highly maneuverable work vehicles with short wheelbases, such as skidsteer vehicles, have proven to be extremely useful for a wide range ofagriculture, construction and industrial projects and are considered tobe among the most versatile work vehicles available. Such vehiclestypically include a rigid frame, independently driven sets of right andleft wheels, an operator cab, an engine, a hydraulic system, and liftarms to which a variety of attachments can be joined (e.g. buckets,trenchers, etc.). The overwhelming success of these skid steer vehiclescan be traced to a large extent to the maneuverability of steering andcontrol, speed, suitability to a variety of environments,interchangeability of attachments, and generally rugged design.

Despite the many advantages offered by these vehicles, they also havelimitations because of configuration or design. There are alsoproblematic safety considerations. For example, when a skid steervehicle lifts an item with a boom, bucket, or other attachment, the sizeof the load that can be safely moved may be compromised by therelatively short wheelbase of the conventional skid steer vehicle. Theshort wheelbase often does not provide a sufficiently stable structureor counterweight to prevent tipping or other unwanted movement.Similarly, traversing steep terrain in a vehicle with such a shortwheelbase, particularly when carrying a load, can present problems.Although various trucks and vehicles with wider wheelbases have beenused for various tasks in the past, these vehicles generally havegreatly diminished maneuverability and agility of operation. Trucks andconstruction vehicles have been proposed with extendable wheelbases orbody members. However, these vehicles generally have a longer steeringradius than a skid steer and are less maneuverable. This limits theusefulness of such machines.

Traditional skid steer steering systems also have drawbacks related tothe wear and tear they can cause on a work site. Standard operation maycause the vehicle wheels to dig into the ground, particularly if theground is soft turf. A steering system and design that takes intoaccount and adjusts to a diversity of operating environments and whichis compatible with the surface on which it is operated is desired.

Because of the many potential circumstances in which work vehicles mustperform, and because of the hazards inherently present in certainconstruction environments, a vehicle which overcomes such hazards ishighly desired. For example, operators of work vehicles of the class areknown to attempt to traverse inclines which may be too steep, lift loadsthat may be too heavy for the circumstances, drive vehicles withunfamiliar controls that are hard to manage, or operate in areas wherevisibility is limited or impaired and may contribute to a situation thatis unsafe. The capability to sense and avoid marginal or unsafesituations is clearly important to work vehicle operators. Generally,current designs are not able to cope with these hazards and most presentwork vehicles provide little ability to adapt or adjust the vehicle toaddress such dangers. For example, if a front end loader were to becomeunstable because a load lifted was too heavy, an operator would havelittle choice but to rely on his or her quick reflexes to rapidlyrelease the load to prevent the vehicle from tipping.

Therefore, it remains desirable to offer a work vehicle which providesgreater versatility, effectiveness and safety. An improved work vehicleis needed which overcomes the problems and limitations experienced inpast methods and devices.

SUMMARY OF THE INVENTION

The present invention provides extendable frame work vehicles offeringenhanced versatility, safety and effectiveness. The vehicles include anadjustable wheelbase, a plurality of steering modes, and independentlydriven wheels. The work vehicles also have variable weight distributionsystem which can be employed to compensate for different weights liftedby the vehicle to different heights and angles dictated by a variety ofwork attached implements and terrain conditions. Finally, anelectro-hydraulic system is provided including a sensor-responsivemicroprocessor controller, a plurality of sensors, at least onehydraulic pump, at least one hydraulic drive motor, and a valve network.The electro-hydraulic system enables variable extension and retractionof the wheelbase, drive and, steering of the wheels in various modes,and use of a variety of frontward and rearward attachments, all with aneye toward improved safety.

The invention further contemplates a variety of work vehicle embodimentsand vehicle and attached implement combinations which are able to safelyallow greater lift load capacities and offer safe operation in terrainconditions involving slopes and other undesirable variations.Embodiments include those equipped with adjustable boom arms, GPSsystems with attachments for monitoring and determining work locations.

It will be recognized that important aspects of the present developmentenable a variety of tasks requiring different implements to beaccomplished with a single vehicle by changing attached implements orauxiliary systems. Additionally, as indicated, the present developmentexpands the safe capacity of vehicles with respect to many of the tasks.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a work vehicle embodiment in accordancewith the present invention shown in a compact or fully retractedconfiguration;

FIG. 2 is a side view of the work vehicle as in FIG. 1;

FIG. 3 is a side view of the work vehicle of FIG. 1 with a secondaryextension deployed;

FIG. 4 is a side view of the work vehicle of FIG. 1 with a primaryextension deployed;

FIG. 5 is a side view of the work vehicle of FIG. 1 showing both aprimary and secondary extensions deployed;

FIG. 6 is a bottom view of the work vehicle of FIG. 1 in a fullyretracted configuration;

FIG. 7 is a bottom view of the work vehicle of FIG. 1 with the secondaryextension deployed;

FIG. 8 is a bottom view of the work vehicle of FIG. 1 with the primaryextension deployed;

FIG. 9 is a bottom view of the work vehicle of FIG. 1 with both theprimary and secondary extensions deployed;

FIG. 10 is a perspective view of the work vehicle with both the primaryand secondary extensions deployed and including an extendedmulti-section boom lift arms;

FIG. 11 is a side view of the embodiment of FIG. 10 with partial cutawaysections of the work vehicle with extended boom lift arms;

FIG. 12 is a view, partly in section, of the cab of the work vehicle ofFIG. 1 disclosing a rear view LCD screen and a GPS screen;

FIG. 13 is a perspective view of the work vehicle of FIG. 1 disclosing arear view camera location;

FIG. 14 is a perspective view of the work vehicle as in FIG. 10including a manlift control box attachment in an extended configuration;

FIG. 15 is a perspective view of the work vehicle showing a retractedconfiguration with a forklift attachment;

FIG. 16 is a side view of the work vehicle configuration of FIG. 15 in aretracted position with a forklift;

FIG. 17 is a perspective view of the work vehicle of FIG. 15 shown in anextended lifting position;

FIG. 18 is a side view with parts cut away section of the work vehiclein a retracted configuration with a slideable forklift attachment;

FIG. 19 is a perspective view of the work vehicle in an extendedconfiguration with a slideable forklift attachment in a raised position;

FIG. 20 is a perspective view of the work vehicle fully retracted withan extendable forklift attachment lowered;

FIG. 21 is a perspective view of the work vehicle in an extendedposition with an extendable forklift attachment in an extended, raisedconfiguration;

FIGS. 22-26 depict various alternate implement attachment arrangementsfor the work vehicle;

FIG. 27 is a bottom view showing the one method of the steering systemlayout of the work vehicle in a retracted position;

FIG. 28 is a bottom view of the one method of the steering system layoutof the work vehicle depicting front wheel steering and the wheelbaseextended;

FIG. 29 is a bottom view of the steering system layout of the workvehicle showing rear wheel steering and the wheelbase extended;

FIG. 30 is a bottom view of the steering system layout of the workvehicle illustrating crab steering and the wheelbase extended;

FIG. 31 is a bottom view of the steering system layout of the workvehicle using Bi Directional steering and the wheelbase extended;

FIG. 32 is a schematic control diagram of a steering system for the workvehicle;

FIG. 33 is a schematic control diagram of a drive system and a frameextension system of the work vehicle;

FIG. 34 is a schematic side view setting forth various sensors of thework vehicle;

FIG. 35 is a schematic control diagram of a lift mechanism system of thework vehicle;

FIG. 36 is a bottom view showing parts of the electro-hydraulic layoutof the work vehicle;

FIG. 37 is a perspective view illustrating parts of theelectro-hydraulic layout of the work vehicle;

FIG. 38 is a view partly in section of a work vehicle load levelingapparatus;

FIG. 39 is an enlarged fragmentary view of the circled, highlightedsection of FIG. 38 showing parts of the work vehicle load levelingapparatus;

FIG. 40 is a rear view of the work vehicle showing the load levelingapparatus and terrain;

FIG. 41 is a bottom view of the work vehicle showing the load levelingapparatus;

FIG. 42 is a rear view similar to FIG. 40 showing a highlighted, circledsection of the work vehicle load leveling apparatus;

FIG. 43 is an enlarged fragmentary view of the highlighted section ofFIG. 42;

FIG. 44 is a bottom view of the work vehicle load leveling apparatus ona vehicle showing the frame extended;

FIG. 45 is a greatly enlarged fragmentary view of the parts highlightedin FIG. 44;

FIG. 46 is a side view of a three-point hitch and power take-off (PTO)on an extendable frame work vehicle of the present invention shown in aretracted configuration;

FIG. 47 is a perspective view showing the PTO and three-point hitch ofthe work vehicle;

FIG. 48 is a schematic control diagram of a PTO system for the workvehicle;

FIG. 49a is a partial cut-away side view of the three-point hitch andPTO of the work vehicle;

FIG. 49b is an isolated interior view of the three-point hitch and PTOassembly of the work vehicle;

FIG. 50 is a perspective view of a remote control device for thethree-point hitch and power take-off (PTO) of the work vehicle;

FIG. 51 is a side view showing the three-point hitch and PTO on the workvehicle with a primary extension deployed;

FIG. 52 is a side view showing the three-point hitch and PTO on the workvehicle with bucket raised and partially extended and both the primaryand secondary extensions deployed;

FIG. 53 is a side view of the three-point hitch and PTO on the workvehicle with the PTO and hitch connected to a spreader attachment;

FIG. 54 is a perspective view of the three-point hitch and PTO on thework vehicle with the PTO and hitch connected to a spreader attachment;

FIG. 55 is a side view of the three-point hitch and PTO on the workvehicle with the PTO and hitch connected to a harley rake typeattachment;

FIG. 56 is a perspective view of the configuration of FIG. 55 where thePTO and hitch are connected to a harley rake type attachment;

FIG. 57 is a schematic control diagram of a three-point hitch system ofthe work vehicle;

FIG. 58 is a side view of an embodiment of a work vehicle equipped witha vertical idler track arrangement in a retracted configuration;

FIG. 59 is a perspective view of a work vehicle with a vertical idlertrack arrangement in a retracted configuration as in FIG. 58;

FIG. 60 is a side view of the work vehicle of FIG. 58 with a verticalidler track arrangement shown in an extended configuration;

FIG. 61 is a perspective view of the work vehicle with a vertical idlertrack arrangement in an extended configuration;

FIG. 62 is a side view of an embodiment of the work vehicle with atorsion idler arm track arrangement in a retracted configuration;

FIG. 63 is a perspective view of the work vehicle with a torsion idlerarm track arrangement of FIG. 62 in a retracted configuration;

FIG. 64 is a side view of the work vehicle with a torsion idler armtrack arrangement of FIG. 62 in an extended configuration;

FIG. 65 is a perspective view of the work vehicle with a torsion idlerarm track arrangement of FIG. 62 in an extended configuration;

FIG. 66 is a side view of an embodiment of the work vehicle with adouble torsion idler arm track arrangement in a retracted configuration;

FIG. 67 is a perspective view of the work vehicle with a double torsionidler arm track arrangement of FIG. 66 in a retracted configuration;

FIG. 68 is a side view of the work vehicle with a double torsion idlerarm track arrangement of FIG. 66 in an extended configuration;

FIG. 69 is a perspective view of the work vehicle with a double torsionidler arm track arrangement of FIG. 66 in an extended configuration;

FIG. 70 is a perspective view of the work vehicle utilizing individualrubber track wheel members; and

FIG. 71 is an overall schematic block control diagram of work vehiclesystems.

DETAILED DESCRIPTION

The present invention can be readily understood from the aforementionedfigures, the following detailed description and certain embodiments ofthe present invention. It will be appreciated that the detailedembodiments are meant only as examples and are not intended to limit thescope of the concepts in any manner.

FIG. 1 sets forth the basic assembly of the work vehicle in itsretracted configuration. In general, the overall appearance of thevehicle may resemble a typical skid steer design when in a retractedstate. Although many of the vehicle's features are concealed in thiscontracted disposition, some of the work vehicle's basic structure canbe appreciated from the perspective view of FIG. 1 and the side view ofFIG. 2.

The work vehicle 10 generally, as will become apparent, includes a framehaving a front portion 14 and a rear portion 16. Front portion 14 of theframe supports a lift arm assembly 21 (FIG. 2), an operator's cab 22,side housing members 23, and much of the physical structure of the frontsection of the vehicle. A set of wheels comprising wheels 18 and 20(FIG. 6) support the front portion of the frame. As used throughout thisspecification, a “set of wheels” may also refer to any suitable numberof wheels, e.g. one or more.

The lift arm assembly 21 includes a pair of lift arms 24 and an attachedbucket 26. Although a pair of lift arms is the primary type of liftmechanism shown in the examples of this application, it will beappreciated that other well-known lift members including booms, cranes,or other like members, may be used as well. Likewise, when the liftmechanism used includes a pair of lift arms 24, it will be appreciatedthat a vast array of industry standard implements (other than the bucket26 shown) can be attached to the lift arms 24 and used with the vehicle.The lift arms 24 pivot at their base in a well known manner to liftimplements using a pair of actuators such as hydraulic cylinders 28.These cylinders 28 may be found on the right and left sides of the workvehicle. An implement such as bucket 26 may likewise be rotated throughan angle at the end of lift arms 24 through use of another actuator suchas hydraulic cylinder 30. This type of angular adjustment is useful fordumping material from bucket 26 or leveling its contents. In somedesigns, it is also possible to extend the lift arms 24 themselves in atelescoping manner as shown in FIG. 10, for example. Extendable liftarms with a plurality of telescoping segments can be used to enable thedevice to reach greater heights. The extendable lift arms will bediscussed later in greater detail.

The work vehicle 10 is equipped with a reinforced operator's cab 22which is constructed to maximize the safety of an individual using thevehicle. The cab 22 includes a rollover protection cage 32 includingboth right and left side supports and a roof 34 with a retractable cover35 for the sunroof opening 36. A sunroof opening 36 provides greatervisibility while the cover 35 helps shield the operator from fallingdebris. A screen may also be provided across the opening for safetyreasons. Large front and rear windows 38 also provide good visibility inthe forward and rearward direction and aid the user's ability to spotpotential dangers. These windows 38 are designed to remain unobstructedby vehicle components in most circumstances.

Side housing members 23 provide rigid structural supports on both theright and left sides of the work vehicle. These members are found at therear of cab 22 and provide support locations for pivotal engagement ofthe lift arms 24 and the lift arm cylinders 28. The side housing members23 are fixed to the front portion 14 of the frame and so do not move inrelation to the front portion 14 during expansion/retraction operation.

Other components, including internal components and lower housingmembers not readily viewable in FIGS. 1 and 2, are also housed on thefront portion 14 of the vehicle frame. These will be discussed later ingreater detail in connection with other drawing figures.

The rear portion 16 of the frame is supported by a set of wheelscomprising wheels 40 and 42 (FIG. 6). The rear portion 16 includes arear multifaced housing 44, an interior assembly 46 constituting thecentral rear structure of the work vehicle, and a number of otherhousing and working features.

As can be seen in the figures, the rear multifaced housing 44 is therearmost feature of the work vehicle. The multifaced housing's outwardprotrusion narrows in width and provides a condensed tail section thathas largely inwardly grooved features, rather than outwardly projectingcomponents that might interfere with operation. One will understand thatthe rear multifaced housing 44 will provide for a certain amount of airflow for proper ventilation of the radiator. The compartments andgrooved features found within the rear face of housing 44 are shaped toaccept a unique three-point hitch and power take-off shown, for example,in FIG. 26 which can optionally be provided. The three-point hitch andpower take-off can be added at the time of manufacture or retrofit at alater time. Embodiments that utilize the compartments and groovedfeatures of the rear multifaced housing 44 to incorporate a three-pointhitch and power take-off are later described in this application.

As will become apparent, the interior assembly 46 of the rear portion 16includes many of the internal features that enable the drive, steering,and other electro-hydraulic systems to function. These features mayinclude an engine 48 (not shown), hydraulic pumps, and other hydrauliccomponentry. As carried by the rear portion 16, the weight of thecomponents of the interior assembly 46 enable it to be effectivelyutilized as a counterweight to loads experienced by the vehicle's liftarms 24.

The front portion 14 and rear portion 16 of the frame are engaged withone another in moveable relation. More specifically, the two portionsare generally moved with respect to one another via a centrally-mountedhydraulic actuator referred to as telescoping device 50.

The present invention has the ability to extend its frame in a varietyof configurations. The basic three extended configurations can be morefully understood with reference to FIGS. 3-5. Often an operator of thework vehicle will desire to lift a load or traverse an incline whichmight cause the vehicle to become unstable in its short wheelbaseretracted state. The present invention therefore, allows an operator torapidly extend or deploy a counterweight load from the back of thevehicle in one configuration, to extend the wheelbase in anotherconfiguration or combine them in a third configuration to counteractpotential instability. Such extension is able to be performed by eitheroperator or automated control.

FIG. 3 discloses the work vehicle of the present invention where thevehicle's secondary extension assembly or secondary counterweight 52 hasbeen deployed in a rearward manner. The secondary extension assembly orsecondary counterweight 52 may be referred to as a separate portion ofthe frame in some embodiments. The secondary counterweight 52 includesfeatures found at the back end of the rear portion 16. The mostsignificant feature being the rear multifaced housing 44 and its lowercounterweight bumper 54 which is contained within the confines ofhousing 44. The bumper 54 may account for a substantial amount of theweight of the secondary counterweight 52.

When it is extended, the secondary counterweight protrudes from the rearinterior housing assembly 46. Interior housing assembly 46 remainsstationary and does not move with the secondary extension assembly 52 inthis configuration or mode. The secondary counterweight 52 is able toperform such movement by actuation of a pair of lower hydraulicallyextendable actuator support members 56 located at the bottom sides ofthe back of the device and the upper extendable actuator. See FIG. 53,for example. The support members 56 cannot be readily viewed from theexterior of the vehicle as they are concealed by a corrugated shroudmember 58. This corrugated member 58 has a width slightly less than thebase for the vehicle and a height that matches the interior housing 46.Contained within the corrugated member is primarily the set ofextendable actuator support members 56. (See FIGS. 11 and 36) While twoactuator members are generally shown in the figures of this application,such a set of actuator support members 56 may include any number of oneor more such members as desired to carry out this extension. Aboveshroud member 58, a narrower, centrally located corrugated shroud member60 extends across the expanse between the work vehicle interior assembly46 and rear multifaced housing 44. Both shroud members 58 and 60 areextendable, retractable, and contain a plurality of holes 62 which allowconsiderable airflow around the covered components.

In addition to actuator support members 56, the rear multi-faced housing44 is also supported by a set of connecting cylinders 64. Theseconnecting cylinders 64 are each double-acting multistage cylindersextending between side supports 66 of the interior assembly 46 and themultifaced housing 44. Such a set may comprise one or more suchcylinders. A set of connecting cylinders as at 64 shown in the figuresof this application generally includes a pair of connecting cylinders onboth right and left sides of the vehicle. These extra supports 64 helpsupport the weight of the secondary counterweight 52. Also, theconnecting cylinders 64 utilize oval swivel end connectors 68 at theirends. (See FIG. 4) Those connectors 68, together with a sensor system,can cause the connectors to lock in position when the system senses thatthe load and/or implement on the lift arms is too heavy or thatexcessive upward and collapsing force is being applied to theconnectors. If necessary, the rear extension counterweight will then belocked in place to maximize that counterbalance or to maintain itsposition.

In general, the secondary extension counterweight 52 is somewhat heavyprimarily due to the lower bumper member 54. When extended, the rearwardmovement of the secondary extension assembly causes an increasedrearward counterbalancing force to a load lifted at the front of thevehicle. Therefore, when an operator causes a load to be lifted ormaneuvers over terrain requiring more substantial force at the rear ofthe vehicle, the operator may simply activate the actuator members 56from within the cab to deploy the secondary counterweight 52 from withinthe cab 22. Actuation of these actuator members may likewise be carriedout in an automated fashion based upon sensors and an extension controlsystem later discussed.

Another configuration of the work vehicle of the present inventionoccurs when the primary extension member 70 (FIG. 5) is deployed, asseen in FIG. 4. In this mode the entire rear portion 16, including thewheels 40 and 42, the interior housing 46, and rear multifaced housing44 have been shifted rearward together. The rear portion 16 moves tothis position based upon actuation of the telescoping device 50centrally disposed on the bottom of the assembly. As seen in FIG. 4, thetelescoping device 50 includes a first hydraulic member cylinder orbarrel 72 that is mounted to the front portion 14 of the housing. Thetelescoping device 50 also includes a moveable stage member 74 that isconnected to the rear portion 16. The primary extension mode may beachieved when the operator utilizes the vehicle's electro-hydraulicassembly including a hydraulic pump and valve network within theassembly to cause the member 74 to extend outwardly from cylinder 72.When the member 74 is fully deployed, a vehicle with entirely differentstructure and properties results.

The vehicle's extension of the rear portion 16 is aided by a set ofconnecting cylinders 76. One of these connecting cylinders is located onthe right side of the vehicle and one connecting cylinder is located onthe left side of the vehicle. These connecting cylinders, likeconnecting cylinders 64, are double-acting cylinders that generallyextend and retract as the respective vehicle extends or retracts. Theconnecting cylinders 76 are attached to a location within the sidehousing members 23 and to the side supports 66 of the interior assembly46. The connecting cylinders 76 may have more extension length than thelower telescoping device 50 which allows the rear end of the device tobecome free floating in most applications. The double-acting connectingcylinders 76 are enabled to make adjustments so that the frame portionscan be properly maintained. Generally when a load is experienced on theback of the vehicle, as on the three-point hitch for example, a sensoris used to detect that load and to cause the connecting cylinders 76 toretract or extend based on that sensor data. By performing in this way,the connecting cylinders help to maintain the structural integrity ofthe vehicle, especially when the wheelbase is extended.

Also seen in FIG. 4, is a corrugated shroud member 78. This corrugatedshroud conceals the expanse and internal components between the cab 22and the side supports 66 of the interior assembly 46. This shroud, likethe shroud members 58 and 60, is extendable, retractable, and contains aplurality of holes 62. When the vehicle is extended, the combination ofboth the stability gained from the longer wheelbase and larger loadhandling ability due to counterweight relocation provides a vehicleconfiguration which has greatly increased effectiveness.

The vehicle configuration shown in FIG. 5 discloses both the primaryextension 70 and secondary extension 52 deployed from the vehicle. Bylengthening the vehicle and its wheelbase with both extensions, thestability of the vehicle is further maximized as an even greater loadmay be handled by the lift arms 24 and bucket 26 at the front of thevehicle. Deployment of each of these extensions may be controlledentirely from within the cab 22 of the work vehicle by the operator.Automated deployment of one or more of these extensions may be enabledas well.

FIGS. 6-9 set forth a bottom view of the work vehicle in four modes ofconfiguration. These include the vehicle's retracted mode, secondaryextension mode, primary extension mode, and combined primary andsecondary extension mode, respectively. These figures allow operation ofthe vehicle frame to be readily understood.

In the perspective view of FIG. 6, the work vehicle's front lower bodymember 80 and rear lower body member 82 are situated directly adjacentone another. Front wheels 18 and 20 extend from opposing sides of thefront body member 80 and rear wheels 40 and 42 extend from opposingsides of the rear body member 82. The bucket implement 26 is located atthe front of the work vehicle and the multifaced housing 44 is locatedat the rear of the vehicle. The short wheelbase of the retracted modeshown here allows a highly maneuverable vehicle which may operate inskid steer mode.

The secondary extension assembly or counterweight 52 is deployed in thebottom view of FIG. 7. As discussed previously, beneath the corrugatedshroud 58 the lower hydraulically extendable support members 56 (notshown) have been extended to move the multifaced housing 44 and rearbumper 54 away from the rear body of the vehicle. The wheelbase of thework vehicle is not extended in this mode and the body members 80 and 82remain adjacent one another.

In FIG. 8, the primary extension 70 has been deployed. Front body member80 is separated from the rear body member 82 via the telescopic actuator50. The primary extension may be deployed either manually or in anautomated fashion.

FIG. 9 simply shows a bottom view where both the primary extension 70and the secondary extension assembly 52 are fully extended. Both anexpanded wheelbase and extended counterbalancing load are present. Thismode provides a maximum amount of stability and rear counterbalancingforce for loads lifted by an implement at the front of the work vehicle.

FIGS. 10 and 11 disclose the use of telescoping lift arms 84 to reachobjects a greater distance from the vehicle and to reach greaterheights. As seen here, the vehicle is operating with extensions fullydeployed. The telescoping design of these lift arms 84 enablessignificant heights to be reached and only a minimum amount of space tobe occupied when stored in the retracted mode. Although a pair of triplesegment or stage arms is disclosed here, a set of single stage or doublestage lift arms are contemplated as well. In either case, these boomdesigns must be rigid enough for push/pull digging operations and havesynchronized side to side hydraulic movement.

The telescoping arms 84, like the standard loader arms 24, are able tobe pivotally raised and lowered using hydraulic actuators 28. Also,implements mounted at the outstretched end of the arms 84 have theirtilt governed by hydraulic actuator 30. The actuator 30 allows forfunctions such as self-leveling of a bucket or implement. Hydraulicpulsing of this actuator supplies bucket shaking functions as well.

The lift arms 84 are enabled to extend in a telescoping manner. Theseextendable arms have a rectangular cross section and are built tosupport a significant load. Hydraulic lines 86 are secured along atleast one of the work vehicle's lift arms to provide power to thehydraulic actuator 30. The hydraulic lines 86 are held down so that theymay be extended and retracted as the triple length lift arms 84 areextended and retracted. This process is aided by a mechanism 88 foundwithin one of the side housing members 23. The mechanism 88 winds up orlets out hydraulic lines 86 from a grooved drum member when necessary.This mechanism can be seen in greater detail in the view shown in FIG.37.

FIG. 11 discloses a partial cut away view of the triple lift arm 84 toprovide further insight as to its structure. More specifically, apartial cross-section is shown of the triple extension member 84 as wellas a partial cross-section of the lower back end of the work vehicle.The three part telescoping member contains cylinders 90, 92, and 94inside the larger outer triple extension 84. These hydraulic cylindersallow for precise, smooth, and detailed movements and operations by thelift arms 84.

FIG. 11 also provides a partial cut away view of the lower back end ofthe work vehicle where both the primary and secondary extensions areextended. One of the actuator support members 56 and the counterweightbumper 54 can be seen as well. The second actuator support member 56 ofthis embodiment is not shown, however that support member is identicalto the member 56 shown and is located in parallel relation to thatmember.

FIGS. 12 and 13 disclose use of a GPS system and a rearview camera inthe present invention. In FIG. 12, a cross section of the cab andvehicle shows a rear view LCD screen 96 in the upper left corner of theoperator's cab 22. This screen is able to be easily viewed by theoperator of the work vehicle to observe the area directly behind thevehicle. Images displayed on the LCD screen 96 are supplied by thecamera 98 mounted on the rear of the work vehicle, as seen in FIG. 13.This screen 96 is especially useful to an operator when backing up thework vehicle or when visibility is limited behind the operator.

A global positioning satellite (GPS) screen 100 is also seen in FIG. 12.This screen 100 may be located in an operator's upper right corner ofcab 22 in an easily viewable location for an operator. GPS screen 100and information displayed therein allows the operator to preciselypinpoint vehicle location. This is, as is well known, accomplishedthrough use of a receiver mounted in the vehicle which picks up a signalsent out by a plurality of satellites broadcasting location information.Of course, GPS information is useful in a broad range of applications.For example, positioning information would be useful in agricultural orturf applications where an operator wishes to know whether a particularagricultural product, such as fertilizer, has been or needs to beapplied to that location.

Another application for the GPS system might include using the locationinformation in conjunction with topography and terrain information. Suchan application might be used to ensure that a work vehicle burying cableinto the ground is able to do so at a constant depth. It is possible tomake such an operation possible by utilizing a secondary transducer torelay depth information. These and similar applications may also makeuse of a Geographic Information System (GIS) for mapping easements,property lines, and other geographic data. By using such a system anoperator can have certainty of location information when performing aconstruction task without leaving the cab of the vehicle or otherwisedelaying a task to ensure work is being done at an appropriate location.

Use of a GPS system, as set forth in FIG. 12, has numerous otherapplications as well, including acting as a location mechanism for lost,stolen or disabled vehicles. In more general application, informationreceived by the GPS components will be supplied to the vehiclesensor-responsive microprocessor controller for governing the movementof the work vehicle including its steering system, drive system, andlift arm system. The software run on the controller enables the vehicleto utilize geographic information to make operation “smart”.

FIG. 14 sets forth a work vehicle having a manlift control box 102attached to lift arms 84. This manlift 102 can be used to elevate aworker to perform any of a wide range of construction, maintenance,industrial, or general tasks. The controls found in the manlift 102allow the vehicle to be operated from within the manlift 102 rather thanthe operator's cab 22. The manlift 102 will typically only be utilizedwhen the primary extension 70 is extended. Such a configuration isrecommended because the expanded wheelbase will help ensure thatsufficient stability is present for an operator and that there will belittle danger of vehicle tipping.

The present concept may be used with a standard forklift configurationwhere forklift members 104 are mounted as part of an implementattachment 103 at the end of vehicle lift arms 84. That configuration isshown in the side and perspective views in FIGS. 15-17. The implementattachment 103 generally consists of two standard forklift members 104projecting outward from a vertical implement panel 105. Such animplement attachment is extremely useful in well-known industrialapplications for lifting pallets and packages of goods and materials.Specifically, the arrangement seen in these figures is attached to avehicle having telescoping lift arms 84.

FIGS. 18 and 19 set forth an alternate design to the standard forkliftconfiguration. Here, an adaptable fork lift member 106 is slideable fromside to side on a grooved implement attachment 108. Such lateralmovement is extremely useful to a vehicle seeking to align its forkswith holes in a pallet for example. Typically, a conventional workvehicle would need to maneuver its entire body to realign the forks andpallet openings. However, when the attachment 108 is used, all anoperator must do is activate lateral implement movement using anelectrical or hydraulic motor switch. The ability to use such implementattachments is an example of the enhanced versatility of this device. Anoperator is therefore also able to quickly and easily shift loads fromside to side and provide precise and delicate placement of liftedmaterials. Also, seen in FIG. 18 is a partial cross-section of the liftarms 84 showing retracted telescoping cylinders in greater detail. Thistelescoping design provides substantial space savings over vehicleswhich do not have this feature.

FIGS. 20 and 21 set forth yet another attachment mechanism in the formof an extendable forklift assembly 110. This device utilizes expandingsupport members 112 of crisscrossed shape on the right and left sides ofthe implement attachment to extend and retract the forklift implementattachment plate 114 and fork members 116. The support members 112 areable to lengthen their reach by pivoting crossed link members at thecenters and ends of each link of the member 112. Therefore, expandedextension and retraction is possible. Having such an adjustable andmaneuverable fork member enables increased ease of alignment as well asadditional extension of lifted objects when placing these objects indifficult to reach areas.

FIGS. 22-26 disclose a variety of implement attachment arrangements forthe work vehicle. FIG. 22 shows a grapple bucket attachment 118. Thegrapple bucket 118 allows a user to take advantage of the leveling andloading capabilities of a skid steer type bucket while also enabling aplurality of hydraulic grapples to assist in grabbing material.Collection and manipulation of all sizes and types of scrap, trash,objects, and debris are possible.

FIG. 23 shows a rock picker attachment 120. The rock picker attachment120 is highly useful for a variety of commercial, industrial,agricultural, and landscaping jobs. It is specially designed to pick uprocks, bricks, debris, logs, and similar materials. Further, the rockpicker 120 allows for quick and safe dumping of material directly intotrucks or desired areas.

FIG. 24 shows a bale handler implement attachment 122. The bale handlerof FIG. 24 is mounted to the front end of the work vehicle. Thisattachment is intended to carefully handle dry bales, round bales, andwrapped square or round bales. The implement's movement is effectuatedby one or more hydraulic cylinders.

FIG. 25 shows a stump grinder attachment 124. The stump grinder 124allows for fast and efficient removal of tree stumps and the like.Extended wheelbase configurations and extendable arms 84 areparticularly useful for utilizing this attachment arrangement as evendifficult to access stumps can be located, reached, and removed. Becauseof the extended disposition of the lift arms, a significant distance ispresent between the operator and the cutting surface of the implement.Having such an arrangement provides additional safety to the operatorcompared to may past designs.

FIG. 26 shows a trencher attachment 126. The trencher attachment 126provides an enhanced tool for trench digging. This trencher providing alarge amount of control and stability to trench close to buildings,curbs, or other objects, particularly when the expanded wheelbasefeatures are utilized. Here, the trencher arrangement provides the userwith additional safety due to the operator location far from thepotentially dangerous trenching portion of the implement

FIGS. 27-31 discloses one of the steering components methods for thework vehicle in five different steering modes from a bottom view.Obstructing housing features and other components have been largelyremoved for clarity. In FIG. 27, the work vehicle is shown in itsretracted configuration in which a skid steer mode of steering istypically most appropriate. This steering mode may be utilized in thesame way a standard skid steer vehicle would operate. Here, the wheelsdo not themselves turn, but the vehicle is capable of being steered bychanging the amount of power applied to the drive member associated witheach particular wheel. This causes the wheels on either the right orleft side of the vehicle to be turned more quickly or slowly than theopposing wheels. Therefore, the actuators 126 shown in FIG. 27 arelocked in place and do not permit the wheels themselves to pivot. Thereare many benefits to using this skid steer mode and design.Specifically, this mode in some applications is extremely useful whenenhanced speed, control, and maneuverability is desired. The narrowwheelbase and ability to turn in its own tracks using this type ofsteering allows the vehicle to rapidly maneuver around work sites.

In some cases, it may also be desirable to utilize steering modes otherthan the skid steer mode even when the vehicle is in the retractedconfiguration. While the following discussion does not specificallymention using additional steering modes when in the retractedconfiguration, the teachings of the other modes of steering may beapplied to the retracted configuration in some cases as well.

Generally, deployment of the primary extension necessitates additionalsteering beyond the typical skid steer controls to achieve themaneuverability desired. FIGS. 28-31 all show alternative steering modesfor the work vehicle when the primary extension is deployed with anextended wheelbase. A steering mode other than a typical skid steersteering mode is typically desired because once the vehicle is extended,a longer wheelbase will not allow for tight turns if the wheels arelocked in place.

In FIG. 28, a front steering mode is disclosed. In front wheel steeringthe rear set of wheels 40 and 42 do not turn, rather the front set ofwheels 18 and 20 turn to guide the vehicle as desired. The steeringcomponents include four hydraulic actuators 126. Each actuator 126corresponds to one of the four wheels 18, 20, 40, or 42. The movement ofthese actuators is governed by a vehicle controller 142 and a valvenetwork which regulates the hydraulic pressure provided to eachindividual actuator. In front wheel steering, the hydraulic actuators126 are pivotally coupled to steering arms 128. Each of the steeringarms 128 pivots on a lynch pin 130 and controls the rotation of thewheel axle 132 for each individual wheel. Therefore, because eachhydraulic actuator 126 is independently controlled, each wheel may beindependently controlled with the steering linkages described. In thefront steering linkage shown in FIG. 28, the actuators 126 governingmovement of the wheels 18 and 20 are supplied hydraulic power to directsteering and the rear wheels 40 and 42 are held in placed by theircorresponding actuators 126.

The front wheel steering mode may be selected on a control panel in cab22 by an operator. In this mode, the front wheel axles may be turned inresponse to a command from a joystick in the operator's cab 22. In frontwheel steering mode, the position of the rear axles is monitoredcontinually and fine adjustments are made by the system to ensure thewheels are kept straight. An operator may switch to this position at anytime in the field and the rear set of wheels will straighten upautomatically regardless of the position of the front set of wheels.

Front wheel drive steering has numerous advantages for a variety of workrelated tasks. This steering mode might typically be used in landscapingtype projects or when the vehicle is being used to haul a trailer. Forexample, one can connect a rake to the front of the vehicle and a seederto the back of the vehicle so that as the vehicle moves, the rakeprepares the soil for seeding and the seeder lays down the seed.

In FIG. 29, the work vehicle is seen in a rear vehicle steer mode. Inrear wheel steering, the front wheels 18 and 20 do not turn but the rearwheels 40 and 42 do turn to permit steering of the vehicle. In thiscase, the actuators 126 corresponding to rear wheels 40 and 42 areutilized. Operator or sensor controls utilize the system controller andcorresponding valves to direct hydraulic fluid to be supplied for thedesired movement of the wheel actuators. These controls also preventmovement of the actuators 126 corresponding to wheels 18 and 20. In rearwheel steering mode, the rear wheels 40 and 42 can be steered manuallyand independently of the front ones. When the work vehicle is in thismode, a manual steering control can be utilized to steer the rearwheels. This is useful for maneuvering in tight corners and may also beuseful to offset the rear wheels slightly when working on steep sidebanks to help prevent the work vehicle from slipping downhill. Oneexample where rear wheel steering might typically be used is where thevehicle is used to load or unload pallets from a truck or trailer.

FIG. 30 is a bottom view of the work vehicle illustrating crab wheelsteering. All the wheels are turned in the same direction to permit thevehicle to maneuver. Such maneuvering is effectuated by coordinating theoperation of all four of the actuators 126 governing all four wheels.Directional steering is sometimes also referred to as sidle or crabsteering, which allows the vehicle to move sideways. This type ofsteering may sometimes be useful to maneuver in buildings or in tightcorners in fields. The rear wheels 40 and 42 are electronicallymonitored and positioned to synchronize with the front wheels 18 and 20.Such steering might also be useful when the vehicle is operating onfinished grades and turf or newly poured concrete or asphalt so that thevehicle does not damage the surface on which it is operating.

FIG. 31 shows the work vehicle in a fifth steering mode, Bi Directionalsteering. In this mode, the front wheels are able to turn one way whilethe rear wheels turn the other way. As in crab steering, turning of thewheels is effectuated by coordinating the operation of all fouractuators governing the movement of the four wheels. In Bi Directionalsteering mode (also referred to as all-wheel steering mode) the rearwheels will follow the front ones to provide the tightest turning circlepossible. A method of controller/sensor recognition and easy push buttonadjustment between steering modes allows the wheels to align themselvesautomatically regardless of their current position. Because of thesmooth turning of the four steerable axles 132, damage to turf or othersurfaces is minimized, spillage of loose materials is reduced, and tirewear is lessened. These advantages can lower or even eliminate groundrework while extending tire life.

The controls for the Bi Directional steering mode synchronize the axles132 of the front wheels 18 and 20 with the axles 132 of the rear wheels40 and 42 to achieve the same steering angle when in Bi Directionalsteering mode. Further, the controller 142 coordinates the wheel axlesto the center position and locks them in place when switching to thismode. In order to achieve synchronized steering by the actuators 126 ateach wheel, electronic position feedback is provided at each wheel oractuator. Bi Directional steering is often useful in cases where heavyloads are being carried and the vehicle must be maneuvered in a tightlocation.

In general, the operation of the work vehicle of the present inventionis governed by an elaborate hydraulic-electric assembly. Thehydraulic-electric assembly includes a sensor-responsive microprocessorcontroller, a plurality of sensors, one or more hydraulic pumps, one ormore hydraulic drive motors, and a valve network consisting of aplurality of hydraulic hoses, valves, and valve and pump sensors. Thehydraulic-electric assembly combines a steering control system, drivecontrol system, lift mechanism system, among other systems andcomponents to provide a vehicle with extensive coordinated,sensor-responsive, and software driven capabilities.

An overview of the steering control system 133 can be understood fromthe steering control diagram found in FIG. 32. In general, this systemallows for independent steering of each wheel based on actuatorscontrolled by electro-hydraulic control valves. In FIG. 32, wheels 18,20, 40 and 42 are shown at four spaced locations. Each wheel isconnected to a drive motor 134 and a hydraulic steering actuator 126,where the individual actuators are positioned to govern the steering ofthe individual wheels. A steering angle sensor 136 may be found adjacentto each wheel for detecting the position of each wheel.

Steering of the wheels is thereby implemented when signal inputs fromthe joysticks/manual controls 138 in the operator's cab, the steeringangle sensors 136, and the GPS system 140 are sent to thesensor-responsive microprocessor controller 142. Software contained incontroller 142 is able to determine the hydraulic pressure needed tocoordinate the desired steering movement based upon the inputs.Controller 142 is connected to a pump pressure controller 144 governingthe operation of the pump 146. The controller 142 is also connected to aCAN (Control Area Network) twin-spool valve assembly 148. This CANtwin-spool valve assembly 148 is part of the vehicle's overall valvenetwork and is made up of a plurality of valve sections 150 eachcontaining two spool valves 151. Each valve section 150 has a pressuretransducer 152 at each working port and common P and T transducers 154.An LVDT transducer 156 provides position feedback for each spool. Thespools are pilot operated and double acting. The pilot valve is a 40 HZvoice coil, low power, 3-position, 4-way proportional valve. An embeddedhigh speed processor 158 is provided for each valve section 150. Thespool position can be controlled to maintain flow or pressure within aclosed-loop algorithm as the processors 158 know the spool position andthe pressure differential across the spool.

Consequently, the steering system design utilizing the CAN twin-spoolvalve assembly as shown in FIG. 32 allows a user to independently andintelligently steer each of the four work vehicle wheels 18, 20, 40, and42. The technology provided by such a design, when combined with thehighly maneuverable work vehicle structure discussed thus far, enables awork vehicle with enormous potential and versatility for accomplishingconstruction and industrial tasks.

A suitable motor drive system 160 for the work vehicle is set forth inFIG. 33. This system relies on mechanical valve devices with integralsensors, electronic controllers, and advanced software. The resultingdesign is a completely software driven electro-hydraulic system forcontrolling the vehicle drive.

The independent 4-wheel drive design includes four hydraulic drivemotors 134 which control the corresponding respective wheels 18, 20, 40and 42. For example, the motors may have a 12-15 cu.in./rev displacementsize range and a two-speed motor option which allows the motor to beswitched via an external operator command to a lower displacement.Ratios of 1.5:1 or 2:1 are typical. The two-speed design allows themachine to have high torque during its working mode and high speedduring certain driving modes. The drive motors 134 are wheel motorswhere the tire hub or drive hub is mounted directly to the tapered shaftof the motor. As set forth in the schematic diagram of FIG. 33, thesedrive motors are hydraulically powered by a twin spool valve drivesystem.

A variety of input devices are present in the system for providingvehicle data to the sensor-responsive microprocessor controller 142.Motor speed sensors 164 are located adjacent to each of the drive motors134 for measuring the speed of each wheel 18, 20, 40 and 42. Foundadjacent to each wheel 18, 20, 40 and 42 are steering angle sensors 136for detecting the wheel position. A GPS system 140 mounted to thevehicle cab 22 monitors overall vehicle position. Joysticks/manualcontrols 138 found in the operator's cab 22 dictate the desired steeringmode, speed and direction of the motor drive. Additionally, frameproximity sensors 161, 162, and 163 send data verifying the location ofthe frame extension members.

Therefore, the drive system operates the drive motors 134 when inputsignals are sent to the drive system microprocessor controller 142 fromjoysticks/manual controls 138 in the operator cab 22, from the GPSsystem 140 on the vehicle, from the motor speed motion sensors 164mounted adjacent each drive motor 134, from frame proximity sensors 161,162, and 163 located on the frame extension cylinders, and from thesteering position angle sensors 136 mounted adjacent each wheel. Indoing this, the controller 142 monitors the speed, steering angle, andother factors present at each wheel. Once the operator selects thesteering mode (skid-steer, Bi Directional drive, crab steer, frontwheel, or rear wheel) and drive mode (all-wheel drive, front wheeldrive, rear wheel drive) the controller 142 will load the appropriatesoftware algorithm to perform the desired function.

The controller 122 next provides signals to both a pump pressurecontroller 166 that governs the function of pump 168 and the processors170 contained on each valve section 172 of the CAN twin spool valveassembly 174 of the drive system. The controller 142 and its softwarealso governs the movement of the primary and secondary extensioncylinders 175. The extension cylinders 175 have their own valve sections172 of the twin spool valve 174. It should also be noted that the pump168 may preferably be the same pump for the vehicle pump 146 of thesteering system.

As in the steering drive system 133, the CAN twin spool valve assembly174 is made up of a plurality of valve sections 174 containing spoolvalves 177, a pressure transducer 178 at each working port, and common Pand T transducers 180. Generally, the valve assembly 174 is part of thelarger valve network for the work vehicle. An LVDT transducer 182provides position feedback for each pilot operated and double actingspool of the valve assembly. The spool position can them be controlledto maintain flow or pressure within a closed-loop algorithm as theprocessors 170 know the spool position and pressure differential acrossthe spool. Accordingly, the drive system design 160 uses the twin spoolvalve assembly 174 to provide intelligent drive for the four wheels ofthe work vehicle.

Each wheel controlled by the drive system 160 is independently drivenand the hydraulic flow is accurately controlled. The vehicle can beprogrammed to steer through an arc with the outside wheels drivingfaster then the inside wheels in proportion to the turn radius. Eventhough each wheel is plumbed in parallel to each other, the closed loopcontrol provides excellent traction control and will not allow one wheelto spin and rob power from the other wheels. In all-wheel drive mode,positive traction is maintained at all times. If a wheel is not incontact with the ground, the system will be able to sense this becausethe differential pressure across the drive motor 134 will approach zero.Because the twin spool valve can maintain constant closed loop flow, themotor will continue to rotate at the same speed as the other motors.

The frame extension feature is an important aspect of the work vehicledesign of the present invention. As indicated, by extending thewheelbase via deployment of the primary extension member 70 and/orsecondary extension member or counterweight 52, the operator can realizeadditional machine stability and lifting capacity. This frame may beextended when the vehicle is standing still, driving forward, or drivingin reverse. Importantly, the software governing the frame extensionfeatures may preferably be written to recognize conditions in which itis undesirable or unsafe to execute the frame extension. Consequently,safety and machine integrity are maintained in frameextension/retraction operations.

When primary frame extension is selected and the vehicle is stationary,the microprocessor controller 142 delivers flow to the rear wheel drivemotors and the rear wheel drive speed matches the cylinder driven frameextension speed. When the vehicle is traveling forward during frameextension, the controller 142 will reduce rear wheel drive speed tomatch the cylinder driven frame extension speed. When the vehicle istraveling in reverse, the controller will reduce front wheel drive speedto match the cylinder driven frame extension speed.

These operations are assisted by the cylinder position sensors 161, 162,and 163 which send cylinder position information to the controller 142.Sensor 161 is responsible for detecting the completely retractedposition of the frame, sensor 162 senses the position of the secondaryextension assembly 52, and sensor 163 senses the position of the primaryextension 70.

In some embodiments, the frame extension telescoping actuator member 50may be eliminated with the valve drive system. In such an embodiment, ahydraulically actuated frame lock mechanism can be used to keep theframe in the desired retracted or extended position. When extension orretraction is required, the lock can be released and the drive wheelsdriven as previously described.

Lift arms 24 of the extendable frame work vehicle also utilizeelectro-hydraulic valve technology and a sensor-responsivemicroprocessor controller 142. Generally, proportional type mobiledirectional control valves and low-effort electronic joysticks are usedto control the lift arm and implement functions. The electro-hydraulicsystem controls leveling features such as bucket leveling devices usingself level valves common in the industry. Other features governed by thesystem include extendable lift arms containing either a single stageextendable boom or a multiple stage extendable boom. (See FIG. 11)

Embodiments containing extendable boom devices contain at least onedouble acting cylinder installed in each of the right and left side liftarm structures 84. A valve system provides flow to each cylinder that isnot only variable but also is equal in flow for synchronized movement.Upon joystick input command from the operator, each valve section iscommanded in closed loop flow control mode to provide proportional flowto the joystick position. Valve performance defines the lead/lag of thecylinder travel.

Another embodiment utilizes a telescoping boom design. Telescopiccylinders used in these designs are constructed of consecutive sectionsof steel tubing with successively smaller diameter that nest inside oneanother. The largest diameter section is the main or barrel and thesmaller-diameter sections that move are called stages. In thetelescoping design shown in FIG. 11, section 90 is the barrel andsections 92 and 94 represent successive stages.

Generally the telescopic cylinders will extend from largest stage to thesmallest. The largest stage, with the smaller stages nested inside, willmove first and complete its stroke before movement of the next stage.This procedure repeats until the smallest diameter stage is fullyextended. Conversely, the smallest diameter stage will retract fullybefore the next stage starts to move. This continues until all stagesare nested back into the main.

The telescoping cylinders used in this design may be either singleacting cylinders or double acting cylinders. Single-acting cylindersextend under hydraulic pressure and rely on gravity or some externalmechanical force for retraction. Double acting telescopic cylinders arepowered hydraulically in both directions.

Normally, extension of a double-acting telescoping cylinder occurs inthe same manner as with the single-acting type. Retraction of doubleacting telescopic cylinders is made possible by sealing each movingstage's piston area outside diameter with the next larger stage's insidediameter and building internal oil-transfer holes into each movingstage. The retraction port normally is located in the top of thesmallest stage. A double acting telescopic cylinder design mightalternatively locate both fluid ports in the smallest stage or plunger.

Piston seals on double-acting telescopic cylinders are manufactured froma hard substance such as cast iron, ductile iron, or glass-reinforcednylon to limit abrasion between the oil transfer holes and ports overwhich they must pass. A telescoping cylinder of the type known as aconstant-thrust/constant speed cylinder may be used as well. Typically,the double-acting cylinder will normally extend sequentially with thefirst stage extending fully and then the second stage extending.However, at low pressures (low loads), the telescopic cylinder may notextend in sequenced fashion.

Safety and automation features are an important aspect of the workvehicle design. Greater operator safety and vehicle stability arerealized by the frame extension and the sensing capabilities. Thisvehicle continually sends a variety of feedback items about operatingand loading conditions to the sensor-responsive microprocessorcontroller 142. Inputs include the bucket load, fork lift load,attachment weight, boom angle, boom extension, bucket/fork angle,vehicle angle (front to rear), vehicle angle (side to side), andattachment horsepower consumption. Therefore, automation is possible tocontrol features such as auto bucket shake, load moment indication andmovement limitation, fork lift horizontal movement, and line following.

The vehicle is enabled to sense a payload in the boom by measuring thepressure on the blind or barrel end port and rod port of the cylinderand to calculate the net force based upon the areas under pressure. Thetwin-spool proportional valve used in the work vehicle has pressuretransducers built into each port. The transducers are available duringactuation of the cylinders. A counterbalancing function is inherent inthe programming of the valve, although a safety load holding valveand/or velocity fuse will be required for emergency. These valves do notinterfere with normal cylinder operation and therefore, the boom liftingpressure is sensed by the valve's integral pressure transducer.

As set forth in FIG. 34, a variety of sensors are available to measureangle, slope, and position related to lift arm operation. Locations forthese sensors are selected to prevent damage or failure. Shown in FIG.34 is a bucket cylinder position transducer 202 and a I-Axis boominclinometer 204 which mount to the lift arms 24. Frame extensionposition sensors 206 are noted at the extendable portion of the vehicle,and a two-Axis chassis inclinometer 208 is shown adjacent the operator'scab 22.

The overall operation of the lift arm system 200 can be understood fromthe schematic control diagram of FIG. 35. This lift arm system is partof the larger overall electro-hydraulic assembly of the vehicle. In thissystem, an actuator 30 controlling the implement tilt is connected to afirst valve section 210. A second set of actuator cylinders 28 forraising the lift arms 24 is connected to a second valve section 212.Both valve sections 210 and 212 having a pair of spool valves 213. Theremaining two actuator cylinders shown in the diagram, left boomcylinder 214 and right boom cylinder 216, control the extension of theextendable boom members. These cylinders are connected to a third valveportion 215 and are part of a closed loop flow control with matchedflows for the right and left cylinders.

The lift arm system 200 therefore operates when inputs from thejoystick/manual controls 138, bucket cylinder position transducer 202,single axis inclinometer boom mount 204, two-axis inclinometer chassismount 208, frame extension position sensors 206, and GPS system 140 aresent to the sensor-responsive microprocessor controller 142. Thecontroller 142 executes a software algorithm which provides the desiredoutput signals to the twin spool valve assembly 218 and the rest of thevehicle's valve network. More specifically, the signals are sent to thepump pressure controller 220 that controls the pump 222 and the valvecontrollers 224 that control the function of the valve portions 210,212, and 215. As in the previous drive and steering systems, the pump222 may optionally represent the same pump or an additional pump topumps 146 and 168.

Each valve has a pressure transducer 226 at each working port and commonP and T pressure transducers 228. An LVDT linear transducer 230 providesposition feedback for each pilot operated and double acting spool. Thespool position can be controlled to maintain flow or pressure within aclosed-loop algorithm since the valve controllers 224 know the spoolposition and the pressure across the spool. The independent meter-in andmeter-out capability leverages integrated pressure and spool positionsensor and on-board electronics. The on-board processing anddeterministic control firmware facilitates high speed closed loopcontrol. Closed loop flow meter-in or meter-out, close loop pressure,and a combination of pressure and override control can be used. Softwaredriven hydraulic functions which are possible include electronic loadsensing, electronic counterbalancing, flow sharing, electronic HPlimiting and electronic pulsing (i.e. bucket shaking, etc).

To operate the new work vehicle in the various steering modes discussedin this application, right and left hand joysticks are provided. Theoperator's control panel in cab 22 is equipped with switches or “softswitches” on the interface screen. These soft switches allow forselection of the desired steering mode and allow for customized controlmodes for the right and left joysticks and pushbuttons.

Various joystick controls for the work vehicle systems are possible. Forexample, in an “H” pattern mode, the left joystick controls left sidedrive functions and lift functions, the right joystick controls rightside drive functions and tilt functions. When the operator pushesforward on the left-hand joystick, all four wheels start to spin. If thejoystick continues to be pushed forward and moved to the left, the workvehicle turns left. The vehicle does this by slowing down or stoppingthe two left wheels. The farther left the operator pushes the joystick,the slower the left wheels will move. The opposite is true when movingin reverse. If the operator pulls the stick all the way back, the workvehicle goes straight backwards, but it the operator then moves thejoystick to the left, the right wheels or right track will slow down,causing the work vehicle to turn right. If the operator centers thejoystick and then pushes it to the left, the left wheels will movebackward and the right wheels or right track will move forward. Thisallows the work vehicle to turn around in the smallest possible area.The right hand joystick controls the loader arms and bucket. Pulling thejoystick back raises the arms and pushing it forward lowers them. Movingthe joystick to the left tilts the bucket up, and moving it to the rightcauses the bucket to dump. Auxiliary functions can be handled byjoystick switches typically located on the right joystick.

An optional joystick “S” pattern can be selected. When in skid steermode, the operator pushes the left joystick forward and the work vehiclewill drive forward. When the operator pulls the joystick back the workvehicle will drive backwards. To turn left while driving forward, theoperator pushes the joystick forward and to the left. To turn to theright, the joystick is pushed forward and to the right. To turn leftwhile driving in reverse, the joystick is pulled back and to the left.To turn right in reverse, the joystick is pulled back and to the right.

FIGS. 36-37 set forth partial views of the work vehicle whichdemonstrate one possible hydraulic layout of the work vehicle. Hydraulicpumps 230 are centrally shown located within the vehicle's rear portion16, generally between the rear wheels 40 and 42. Pumps 230 collectivelyrepresent all the hydraulic pumps used in the various systems of thevehicle including pumps labeled 146, 168, 222, 532, and 590. These andpotentially other hydraulic pumps referred to in this disclosure maycomprise one single system pump or a plurality of pumps as the systemrequires. A network of hoses 232 connect these pumps to either a forwardvalve bank 234 or a rear valve bank 236. A series of hoses 232 alsoconnect these valve banks to various hydraulic powered componentsthroughout the vehicle. Some of these hoses are specially looped withplenty of additional length so as to accommodate primary and secondaryextensions of the frame, lift arms, etc. A hydraulic reservoir 238 islocated in the front portion of the vehicle and is responsible forproviding fluid to run throughout the system.

Some components seen in FIG. 36 include the drum shaped mechanism 88 forsupplying hydraulic lines 86 to extendable lift arms such as triplelength lift arms 84. Also, one of the lower hydraulically extendablesupport members is partially shown. The connecting cylinders 64 and 76,which make extension possible, are shown on both sides of the vehicle.

FIGS. 38-45 disclose an embodiment with a leveling arrangement 400 andrelated capabilities of the work vehicle of the present invention. Thework vehicle described in this application will often be required tooperate in environments where rough terrain is present or whereexcavation and construction equipment have left behind ground surfaceshaving significant undulations. In a typical vehicle, this terrain wouldsubstantially undermine the stability and maneuverability of the vehiclebecause the vehicle's center of gravity may be drastically shifted whenthe vehicle wheels pass over the uneven ground. Operations involving thelift arms 24 and implements 26 mounted on the vehicle would not bepossible in many instances. Further, a vehicle operator could notcomfortably sit in an upright manner when traversing uneven ground.

The present invention overcomes the problem of uneven ground surfaces byproviding the option of a leveling arrangement 400. In this levelingarrangement, the work vehicle utilizes an adjustable frame assemblyconsistent with the work vehicle disclosed thus far. Therefore, such anassembly can be described as generally including a first portion such asfront portion 14 and a second portion such as rear portion 16 thatextend and retract with respect to each other. Each of the first portion14 and second portion 16 include a mounting member 402 in the levelingarrangement.

Associated with each the front and rear portions are support assemblies404 and 406. Each support assembly 404 includes a transverse shaftmember 408 pivotally coupled to the mounting member 402 of therespective portion at approximately the center of the transverse shaftmember 408. In FIGS. 38-45 the transverse shaft member 408 can be seenextending across the width of the base of the vehicle. Further, at leastone wheel is operatively coupled to each end of the transverse shaftmember 408. Such operative coupling is generally a pivotal engagementbetween an individual axle 410 associated with each wheel and thetransverse shaft member 408.

In addition to a hydraulic actuator, such as telescoping actuator member50, that extends and retracts the first portion 14 and the secondportion 16 of said frame, additional actuators are also associated witheach support assembly 404 and 406. At least one hydraulic actuator 412pivots the first portion with respect to the support assembly 404associated with the first portion. Also, at least one actuator 412 alsois responsible for pivoting the second portion with respect to thesupport assembly 406 associated with the rear portion.

Therefore, each of the transverse shaft members 408 is pivotally mountedto the work vehicle so that the ends of the transverse shaft members 408and corresponding wheels may vary their height utilizing hydraulicactuators 412. An operator can accordingly manipulate the height of thetransverse shaft members 408 to level the vehicle's cab and frameirrespective of the slope of the ground.

The vehicle's entire cab 22 and main body section is thereby enabled toremain upright and level throughout operation. This system accomplishesthe leveling function with a two-axis frame mounted inclinometer 414(not shown) and one or more hydraulic actuators 412. More specifically,the sensor-responsive microprocessor controller 142 is programmed toprovide the closed loop position of the actuators so that the machinecan be leveled using inclinometer feedback.

FIG. 38 discloses a cross-sectional view through the vehicle where therear wheels 416 and 418 and surrounding leveling apparatus is shown. Thevehicle's left rear wheel 416 is significantly lower than the height ofthe right rear wheel 418. A slanted transverse shaft member 408 can beseen between the two wheels. The transverse shaft member 408 pivotsaround a center pivot point of the mounting member 402 at a lower centerlocation. A single hydraulic actuator 412 is shown mounted to the sideof the vehicle in a vertical orientation. The hydraulic actuator 412extends from a fixed pivot location 420 on the side of the vehicle to alocation on the side of the transverse shaft member 408 between thevehicle housing and the inside the wheel 416. While only one hydraulicactuator 412 is shown on this transverse shaft member 408, it iscontemplated that the load leveling feature of this invention may alsoinclude a second hydraulic actuator mounted on the opposite side of thevehicle just inside wheel 418. In the case of multiple hydraulicactuators 412, these actuators would operate in a coordinated fashion tomaximize vehicle stability and smooth movement of the wheels.

FIG. 39 shows a more detailed view of the load leveling arrangementsurrounding wheel 416. Again, the hydraulic actuator 412 is in anextended configuration which pivots the transverse shaft member 408around a center pivot point of the mounting member 402 of the vehicle.It can be seen that the wheel 416 is not rigidly mounted to thetransverse shaft member 408 but rather the wheel axle 410 is pivotallyengaged to the transverse shaft member 408 at pivot 422. This pivotalengagement not only allows for adjustment of the wheel for steering asmentioned previously, but also enables adjustment of the camber angle ofthe wheel. Adjustment of the camber angle of the vehicle wheel 416 ismade possible by a camber link 424 and the rest of the associatedlinkage. The camber link 424 is found below the transverse shaft member408 and enables camber angle adjustment by the vehicle operator. Similararrangements can be found at each of the four vehicle wheels 416, 418,426, and 428.

FIG. 40 discloses a rear view of the work vehicle where the vehicle ismaking use of the load leveling features of the vehicle. The hydraulicactuator 412 is largely hidden in this view. FIG. 41 shows a bottom viewof the work vehicle having a load leveling configuration. The generallayout, transverse shaft member 408, mounting members 402, steeringlinks 430 and camber links 424 are disclosed.

FIGS. 42-45 set forth views of the work vehicle where its primaryextension has been extended and wheels are being turned. FIG. 42 is arear view of the work vehicle. A close up view of the featuressurrounding wheel 416 are shown in FIG. 43 and a bottom view is shown inFIG. 44. A bottom view close up view of the attachment arrangement ofwheel 418 is shown in FIG. 45 as well.

FIGS. 46-57 disclose an embodiment that features a three-point hitch andpower take-off (PTO) assembly 500. By providing a PTO shaft 512 andthree-point hitch 514, this arrangement supplies additional utility andversatility to the extendable frame work vehicle.

In general, many vehicles such as tractors and other constructionequipment may make use of a PTO or three-point hitch. In fact,three-point hitches may be the most common mechanism for connectinghydraulically actuated mechanical linkages in farm and power equipment.Moreover, there are a wide variety of attachments designed to adapt tothis type of hitch and/or draw power from a PTO.

A PTO is typically a mechanical device that uses a driveshaft containingridges (or splines) to draw power from a work vehicle engine and providethat power to an attachment, second machine, or other auxiliaryequipment. PTOs can be mounted on either a main or auxiliarytransmission. PTOs can also be transmission mounted or engine mounted.For transmission mounted PTOs the PTO is located on the side, bottom, orrear of the transmission. For manual transmissions the PTO is drivenfrom a countershaft gear or reverse idler gear. For automatictransmissions the PTO is driven before the torque converter and issubjected to torque converter slip. An engine mounted PTO is located atthe rear of the engine and can be driven from timing gears or a specialgear train. A hydraulic drive PTO is preferred in the present invention.

The present invention provides a number of challenges to the effectiveimplementation of a three-point hitch and/or PTO. This is primarily dueto the movement of the vehicle's secondary extension 516 which includesthe multifaced housing 518 at the back of the vehicle where one mighttypically expect PTO and three-point hitch features to be located.

If an extendable frame vehicle is used with a PTO and hitch arrangement,a secondary extension as at 516 must be able to support the weightrequired by a three-point hitch, and that the arrangement must notinterfere with the ability to access and run the PTO shaft. Further, themany outwardly projecting features of these devices must not be able todisrupt vehicle operation. Therefore, it is desirable to have anattachment device offering the advantages of a three-point hitch and PTOarrangement yet which can be used with an extendable frame vehicleoffering greater versatility, effectiveness and safety to the operatorand those around the vehicle.

The present invention can be more readily understood with reference toFIGS. 46-57. The attachment arrangement 500 generally includes a PTOshaft 512 and three-point hitch 514. Both of these features areintegrated into the rear multifaced housing 518 of the extendable workvehicle 518.

First, with respect to the PTO shaft 512, there are a number ofimportant design features. The PTO shaft 512 is located at the end of adriveshaft located beneath the housing of the work vehicle 520. Aportion of the PTO shaft 512 can be seen protruding slightly from thevehicle. The PTO shaft 512 is a splined shaft protruding from the lower,center, back of the vehicle. The PTO shaft 512 is surrounded by anoutwardly projecting rectangular shaped shield 524 to guard the shaftfrom its surroundings. This shield 524 is important to keeping the shaftsafe from damage.

Because of the present invention's dual frame extension, a PTO shaftdriven off the engine 522 may not be suitable. Therefore, a hydraulicmotor 526 may be used to power the PTO drive instead. This PTO systemarrangement 528 can be seen in FIG. 48. This configuration isaccomplished by using a dedicated pump/motor combination. A piggy backfixed displacement pump 530 is driven off the main pump 532. This pumpserves both the cooler 534 and filter 536 loop and the optionalhydraulic drive PTO 538. If an optional hydraulic drive PTO 538 is used,a solenoid operated diverter valve 540 may be added to the circuit that,when energized, results in driving the PTO motor.

In general, the PTO operation is made possible when joysticks/manualcontrols 138 are manipulated to send movement input data to thecontroller 142. After running the algorithm programmed in the controller142, output commands are sent to both the solenoid operated divertervalve 540 and the pump pressure controller 542 which governs theoperation of the main pump 532. Consequently, the system set forth inFIG. 48 can operate to readily produce PTO shaft rotation and power toimplements attached to the vehicle. This is true even when the vehiclehas its secondary extension member in use.

Surrounding the PTO is another important feature of this invention'sdesign, a three-point hitch 514. This three-point hitch 514 helps totransfer the weight and stress of an implement to the rear wheels of thework vehicle. The three-point hitch is generally comprised of threemoveable arms. These include a hydraulic cylinder arm called the toplink 544 and two separate lift arm assemblies 546 comprising four-barlinkages. Each of these arms has its own attachment point for connectingimplements to the three-point hitch 514.

An advantageous aspect of the design of the present invention is the waythat the three arms may be stored. When not in use, these arms may beretracted or detached and stored in compartments that are inset withinthe multifaced housing 518. One such storage feature is an uppercompartment 547 located along the upper edge of the housing 518 in whichtop link 544 may be detached and place. Also, two vertical compartments549 extend the length of the lift arm assemblies 546 and allow forretraction and storage of the lift arm assemblies 546.

The adjustable top link 544 (sometimes referred to as the “center link”or “top arm”) is a hydraulic cylinder coupled at one end to theextendable frame portion in pivotal engagement to a bracket 548. Inproximity to the other outwardly extending end of the top link 536 is anattachment point 550 consisting of a hole for attachment to animplement. Implements typically have posts that fit through theattachment point 550. Such an implement will generally be secured byplacing a pin on the ends of the post. The top link 544 is the pivotingpoint of the linkage and is typically an important part of makingimplement adjustments. The top link 544 may be optionally powered by thework vehicle's hydraulic system.

The two lift arm assemblies 546 are also critical components of thethree-point hitch. These lift arm assemblies each comprise a four-barlinkage coupled to an actuator and includes an attachment point 558.More specifically, three of the bars of the four-bar linkage includethree link members that are pivotally joined for useful attachment.These link members of the four-bar linkages include an upper horizontallink 552, a lower horizontal link 554, and a vertical link 556. Links552 and 554 project rearward in a generally horizontal direction frompoints of pivotal attachment to the vehicle's rear multifaced housing518. The outwardly extending ends of each of the links 552 and 554 haveholes 558 that serve as attachment points for an implement attachment.Vertical links 556 pivotally join the horizontal links 552 and 554 toprovide further support. As previously stated, lower links 552 arepivotally attached to the rear multifaced housing 518. However, thispivotal attachment is generally not at the end of a lower link 552, butrather along its length. The ends of lower links 554 are found withinthe multifaced housing 518, where they are pivotally mounted to rightand left hydraulic actuators 560 and 561. Actuators 560 and 561 arehydraulically moved up and down as directed by a vehicle operator andprovide convenient vertical adjustment of the three-point hitchassembly. Using this arrangement provides lift arm assemblies 546 ampleswing flexibility for easy alignment and attachment of an implement.

Although the top link 544 is typically a simple turnbuckle in manythree-point hitches, the present invention contemplates use of ahydraulic cylinder 545 as the top link. This is useful as turnbucklesare often hard to turn under load and are even more difficult to move ifthe arm or threads are rusty, dirty, or bent. The hydraulic cylinder 545connects to the tractor hydraulics with short, small-diameter hoses andallows the operator to change the angle of the hitch effortlessly fromthe control cab. Changing the hitch angle can make it much easier tohitch and unhitch implements and makes a quick hitch even easier to use.It is also useful to adjust the implement angle in the field. While theimplement angle is very important for many applications, drivers oftendo not want to get out of the tractor to attempt to adjust the upperlink. With the hydraulic cylinder 545 of the present invention,adjustment is simply accomplished by the push of a button and is morelikely to be done due to the small amount of effort such adjustmentrequires.

FIG. 50 is a perspective view of a remote control device 562 for thethree-point hitch and power take-off (PTO) of the present invention. Attimes when a vehicle operator is outside the cab, such a remote controldevice 562 is especially useful. In some cases, this will be thepreferred location for an operator performing attachment of a rearimplement or executing PTO operations. Also, operating the PTO by remotecontrol allows an operator to remain a safe distance from moving partsduring use and needing to get into an out of the cab to engage ordisengage the PTO. The remote 562 has buttons 564 and 566 for raisingand lowering the three-point hitch assembly members respectively. Abutton 568 is also provided for activating the PTO. Remote controlsprovided for executing the PTO and three-point hitch may contain furtherbuttons or controls. Moreover, such remote controls might be possiblefor use in performing extension and retraction of the frame itself. Themanlift 102 may also make use of such a remote control for example.

FIG. 51 is a side view of the three-point hitch and PTO attachmentarrangement on an extendable frame work vehicle where the primaryextension is deployed. FIG. 52 is a side view of the attachmentarrangement where both the primary and secondary extensions aredeployed. These arrangements allow confined use of the PTO andthree-point hitch features when the primary or secondary extensions aredeployed. This capability enables numerous previously unavailableconfigurations of various implement attachment arrangements.

FIGS. 53-56 disclose more possible attachment configurations using thethree-point hitch and PTO assembly 500. Specifically, FIGS. 53-54 showside and perspective views of the attachment arrangement where inaddition to the front attachment of the lawn mower 570, the PTO andhitch are being used by a fertilizer spreader attachment 572. FIGS.55-56 show side and perspective views of the attachment arrangementwhere in addition to rock picker 574 the PTO and hitch are being used bya harley rake type attachment 576. Such figures make up a small samplingof the wide range of attachment configurations that may be used by thethree-point hitch and PTO assembly 500.

Operation of the three-point hitch control system 578 may be more fullyunderstood from the diagram of FIG. 57. Four cylinders used by thethree-point hitch are shown. They include the cab tilt cylinder 580, thetop link cylinder 545, right actuator 560, and left actuator 561.

Each of the cylinders is separately connected to its own valve section582 of the of the twin spool valve 584. Also, integral linear positionsensors 586 are separately connected to top link hydraulic cylinder 545,right actuator 560 and left actuator 561.

The three-point hitch control system 578 therefore operates when inputsfrom the joystick/manual controls 138 (including pushbuttons on thejoystick or on the operator interface screen), two-axis inclinometerchassis mount 208, frame extension position sensors 206, and GPS system140 are sent to the controller 142. The controller 142 executes asoftware algorithm which provides the desired output signals to the CANtwin spool valve 584. More specifically, the signals are sent to thepump pressure controller 588 that controls the pump 590 and the valvecontrollers 592 that control the function of the valve sections 582.

Each valve has a thin film pressure transducer 594 at each working portand common P and T pressure transducers 596. An LVDT linear transducer598 provides position feedback for each pilot operated and double actingspool.

Automation of the three-point hitch is therefore also possible. The thinfilm pressure transducers 594 monitor the pressure in the three-pointhitch rod port and cap port. This data can be calculated to achieve loadand lifting force. The operator will have the ability to command thethree-point hitch to “float” at a pre-determined load. By commanding arod port pressure control to the CAN twin spool valve 584 that controlsthe three-point hitch, the cylinder can extend or retract whilemaintaining a constant load transmitted to the turf below the vehicle.

Therefore, the cylinders are controlled by electronic control valveswith command received via a CAN bus from the machine controller 142.This results in rapid and precise control of all attached implementsconveniently guide, adjusted and secured from the operator's cab 22.

By controlling the top link hydraulic cylinder, the operator hasmultiple operational type selections. The operator can select positioncontrol, change the length as a function of lift height or use differentcharacteristics for lifting, lowering or float. This permits automaticsteep and parallel lifting of the implement. Finally, the controllifting cylinder can provide precise implement position even receivingcontrol commands straight from the implement and the lift can assume acounterbalance or float position.

FIGS. 58-70 relate to an embodiment of the present invention utilizingan alternative to a wheeled vehicle in the form of a track arrangement600. The work vehicle includes an adjustable frame having front and rearportions that may extend or retract with respect to each other, avariable base length track assembly with first and second tracks locatedon opposite sides of the vehicle, and an adjustable arm carrying anidler located within each of the first and second adjustable lengthtracks to modify the path of the tracks based on the extension orretraction of the frame. The work vehicle also includes a set of lowertrack wheels located within each of the first and second tracks, anengine mounted on the rear portion of the frame, and a controller whichreceives vehicle data and responds by actuating extension and retractionof the adjustable frame.

Specifically, FIGS. 58-61 show a vertical idler arm configuration 600.In FIGS. 58-59 the work vehicle is in the retracted configuration. Inkeeping with the basic work vehicle structure of this invention, thework vehicle 602 generally includes a first front portion 604 that isextendable and retractable with respect to a second rear portion 606.The work vehicle has a variable base length track assembly 610 thatincludes first and second track members 612 and 614 on the right andleft sides of the work vehicle body. Each respective track member 612and 614 includes a track 616, a front drive wheel 618, and a rear drivewheel 620. The drive wheels 618 and 620 are driven by hydraulic drivemotors (not shown) found at each interior axle of the vehicle. Thesedrive motors are driven at uniform speed and direction with one anotherto provide smooth rotation. The speed of the track 616 is therebygoverned by the speed of the drive wheels. Separate drive wheels anddrive motors are found within the second track member 614. Therefore,manipulation of the direction and speed of rotation of the two trackmembers 612 and 614 allows the vehicle to rotate and maneuver asdesired.

Spaced between these driven wheels 618 and 620 are a plurality of lowertrack wheels 622. The lower track wheels 622 are mounted on anexpandable assembly 623 made up of short metal links 625 pivoted withone another at their ends and midpoints. By linking the lower trackwheels 622 in this way, the wheels are enabled to extend and elongatethe track or retract along the base of the track member 616 in anequally spaced-apart manner.

An adjustable arm which carries an idler 626 is located within each ofthe track members 612 to govern the path of the track members. In FIGS.58-61 the adjustable arm is part of a vertical idler arm assembly 624. Avertical idler arm assembly 624 is centrally located above the lowertrack wheels 622. The vertical idler arm assembly 624 includes an uppertrack tension wheel or idler 626 and an adjustable vertical idler arm628. The vertical idler arm 628 is capable of being moved in and out ofa base 630 in a sliding fashion. The base 630 is affixed to the supportframe 631 centrally located within the track member 612. The trackmember 616 accordingly encircles the driven wheels 618 and 620, thelower track wheels 622, and the upper track tension wheel 626.

FIGS. 60 and 61 disclose a vertical idler arm configuration 600 wherethe vehicle has deployed a multifaced housing extension 632 in arearward manner. Deploying this extension is somewhat analogous to thedeployment of the secondary extension member or counterweight 52discussed above. Moving the housing member 632 in this way enables moreweight to be shifted to the rear of the work vehicle forcounterbalancing loads lifted by a bucket or implement 634 at the frontof the vehicle. Additionally, this extension includes an expansion ofthe track base on which the vehicle sits. The driven wheel 620 isshifted rearward with the housing member 632 and a longer track baseresults. The lower track wheels 622 are spread apart with the help ofexpandable assembly 623. The vertical idler arm 628 of the verticalidler arm assembly 624 has been lowered down into base 630. Thismodifies the track path to provide the necessary slack in the trackmember 616 to accommodate the rearward movement of the rear drive wheel620. An adjustable arm such as the vertical idler arm is responsible forcarrying an idler and is located within each set of tracks. The idlerarm may have its position adjusted using several different means. Insome embodiments, the adjustable arm may be spring biased so that theextension and retraction of the front and rear portions of the frame usethe track to force the idler and adjustable arm downward. Alternatively,the adjustable arm may be hydraulically actuated and controlled incorrespondence to the frame extension and retraction. Whatever mechanismis used, the result is a vehicle having an extended track base thatenables greater loads to be lifted at the front of a more stablevehicle.

FIGS. 62-65 disclose a number of views of the present invention where atorsion idler arm assembly 636 is used in place the vertical idler armassembly 624. Such a torsion idler arm assembly 624 includes a tracktension wheel 638 joined to an adjustable arm referred to as torsionidler arm 640. The torsion idler arm 640 is pivotally joined to thesupport frame 631 such that the idler arm 636 can rotationally pivotwith track tension wheel 638 from a vertical position, as shown in FIGS.62 and 63, to a horizontal position, as shown in FIGS. 64 and 65. Asbefore, this may be done under track pressure against a biased spring orit may be done based upon hydraulic actuation. This operation isperformed when the multifaced housing 632 is moved rearward. Tracklength is therefore extended and a more stable vehicle results. Lowertrack wheels 622 help to support the track 616 between the drive wheels618 and 620. The lower track wheels 622 are kept in parallel spacedrelation along a grooved member 642.

FIGS. 66-69 disclose a number of side and perspective views of the workvehicle of the present invention which utilizes a pair of double torsionidler arms 644 and 646. FIGS. 66 and 67 show the torsion idler arms inthe upright position and FIGS. 68-69 show the torsion idler arms in thehorizontal position with the track 616 having maximum extension. Thetorsion idler arms operate by pivotal movement similar to the movementof torsion idler arm 640 in FIGS. 62-65. By using two idler arms, agreater amount of track can be used. This enables a still longer trackbase to be realized when the vehicle is in the extended configuration.

FIG. 70 sets forth a view of the work vehicle of the present inventionutilizing rubber track members 675. These track wheel members may be ofthe type made by Track Division of National Transmission under thetrademark MATTRACKS® or a similar product of another manufacturer. Suchtracked wheels may be adapted to engage with existing work vehicle wheelmounting components. In doing this, the tracked wheels may substitutefor the driven wheels, of the type shown throughout this application.Using such rubber track members 675 provides the work vehicle of thepresent invention with additional capabilities for maneuvering overvarious worksite surfaces. Utilizing these individual track wheelmembers provides the vehicle with some of the surface engagingadvantages of track members while still allowing some of themaneuverability advantages of individual wheels.

The overall operation and functionality of the work vehicle can beunderstood from the diagram of FIG. 71. A basic overview of the workvehicle system 700 is shown. As disclosed in this figure, a centralcontroller 142 is responsible for governing the overall tasks of thework vehicle. Such a controller may constitute a sensor-responsivemicroprocessor with related control circuitry secured within thevehicle. The controller 142 is able to operate the vehicle by receivingdata in the form of various operator inputs 702 and sensor inputs 704.Some of these inputs being directed relayed to the controller and somebeing relayed via a wireless receiver 706.

The microprocessor controller 142 is loaded with extensive and advancedsoftware which enables the controller 142 to run a valve network 707connected with one or more hydraulic pumps 708. The valve network ismade up of an extensive assembly of valves, hoses, sub-controllers,sensors, and other electro-hydraulic componentry. Valves of mostembodiments will comprise a variety of twin spool valves which run off avariable displacement pump.

The pump 708 may represent one or more of the pumps. In mostembodiments, all of the hydraulic pumps called out by numbers 146, 168,222, 532, and 590 in this patent application are embodied in one or twomain pumps. Those numbered pumps may represent one single pump or anynumber of additional pumps necessary to carry out the pump functions foreach system. The primary systems operated for the work vehicle mayinclude the steering system 710, the drive system 712, the frameextension system 714, the lift mechanism system 716, the load levelingsystem 718, the rear attachment systems 720, and the track system 722.

Those skilled in the art will appreciate that the work vehicle of thepresent invention may be manufactured in a variety of shapes and sizesto accommodate various sizes and types of tasks including variousconstruction projects, etc. The components can be composed of any numberof suitable materials. Also, the design of the present invention shouldnot be construed to limit its application to only construction,industrial, or residential applications.

It will be appreciated that any of the hydraulic systems of the presentinvention, particularly parts that are subject to be connected,disconnected or changed, may also be equipped with specialized,easy-to-connect or quick connect adaptors, fittings and hoses. Thesecomponents enable many hydraulic connections to be quickly and easilyachieved with one touch connections. They are especially useful forvarious embodiments of the vehicles of the present invention which mayhave a large number of hydraulic components confined in a small amountof space or in changing or attaching auxiliary systems to thehydraulics. An example of such a product is the Aeroquip STC(snap-to-connect) hydraulic hose and fitting connection system availablefrom Eaton Corporation of Eden Prairie, Minn. Hydraulic components andhoses throughout the work vehicle can thereby be connected with thesespecial fittings which use specially shaped male and female connectioncomponents.

The invention has been described herein in considerable detail in orderto comply with the patent statutes and to provide those skilled in theart with the information needed to apply the novel principles and toconstruct and use such specialized components as are required. However,it is to be understood that the invention can be carried out byspecifically different equipment and devices, and that variousmodifications, both as to the equipment and operating procedures, can beaccomplished without departing from the scope of the invention itself.

What is claimed is:
 1. A work vehicle comprising: (a) a frame having afirst portion, a second portion and a third portion moveable relative toeach other between an extended position and a retracted position; (b) apower take-off shaft located on and moveable with said third portion ofsaid frame; (c) a hitch located on and moveable with said third portionof said frame, said hitch comprising a first four-bar linkage includinga first attachment point, a second four-bar linkage including a secondattachment point, at least one actuator coupled to said four-barlinkages for adjusting the position of the attachment points of thefour-bar linkages, and a hydraulic cylinder coupled between said secondportion of said frame and a third attachment point wherein said first,second, and third attachment points provide three points for attachmentof a device to the vehicle; and (d) a dedicated hydraulic pump/motorcombination that includes a main pump and an auxiliary pump for drivingthe power take-off shaft.
 2. A work vehicle as in claim 1 furtherincluding a safety shield surrounding the power take-off shaft.
 3. Awork vehicle as in claim 1 further including a remote control forcontrolling the rotation of the power take-off shaft.
 4. A work vehicleas in claim 3 wherein the remote control controls the position of saidfirst and second four-bar linkages.
 5. A work vehicle as in claim 1further including and outer housing and a panel on the outer housing ofthe work vehicle for controlling the PTO power take off shaft and firstand second four-bar linkages.
 6. A work vehicle comprising: (a) a framehaving a first portion and a second portion moveable relative to eachother between an extended position and a retracted position; (b) a powertake-off shaft located on and moveable with said second portion of saidframe; and (c) a hitch located on and moveable with said second portionof said frame, said hitch comprising a pivotally mounted first lift armassembly, a pivotally mounted second lift arm assembly, and a pivotallymounted top link member wherein the first lift arm assembly, second liftarm assembly, and top link each contain an attachment point; (d) aplurality of hydraulic actuators permitting an operator to raise andlower the first lift arm assembly, second lift arm assembly, and the toplink; and (e) wherein the power take-off shaft is driven by a dedicatedhydraulic pump/motor combination that includes a main pump and anauxiliary pump.
 7. A work vehicle as in claim 6 further including aremote control for controlling the power take-off shaft and the firstand second lift arm assemblies.
 8. A work vehicle comprising: (a) aframe having a first portion, a second portion and a third portionmoveable relative to each other between an extended position and aretracted position; (b) a power take-off shaft located on and moveablewith said third portion of said frame wherein said power take-off shaftis driven by a dedicated hydraulic pump/motor combination; (c) a hitchlocated on and moveable with said third portion of said frame, saidhitch comprising a pivotally mounted first lift arm assembly, apivotally mounted second lift arm assembly, and a pivotally mounted toplink member wherein the first lift arm assembly, second lift armassembly, and top link each contain an attachment point for mounting toa work implement; and (d) at least one hydraulic actuator mounted withinsaid second portion for controlling the movement of the first lift armassembly and the second lift arm assembly.
 9. A work vehicle comprising:(a) a frame having a first portion and a second portion moveablerelative to each other between an extended position and a retractedposition; (b) a power take-off shaft located on and moveable with saidsecond portion of said frame; (c) a hitch located on and moveable withsaid second portion of said frame, said hitch comprising a firstfour-bar linkage including a first attachment point, a second four-barlinkage including a second attachment point, at least one actuatorcoupled to said four-bar linkages for adjusting the position of theattachment points of the four-bar linkages, and a hydraulic cylindercoupled between said second portion of said frame and a third attachmentpoint wherein said first, second, and third attachment points providethree points for attachment of a device to the vehicle; and (d) whereinsaid second portion of said frame of said work vehicle comprises aplurality of storage compartments and wherein said first and secondfour-bar linkages and hydraulic cylinder may be retracted into thestorage compartments when they are not in use.
 10. A work vehiclecomprising: (a) a frame having a first portion and a second portionmoveable relative to each other between an extended position and aretracted position; (b) a power take-off shaft located on and moveablewith said second portion of said frame; and (c) a hitch located on andmoveable with said second portion of said frame, said hitch comprising apivotally mounted first lift arm assembly, a pivotally mounted secondlift arm assembly, and a pivotally mounted top link member wherein thefirst lift arm assembly, second lift arm assembly, and top link eachcontain an attachment point; (d) a plurality of hydraulic actuatorspermitting an operator to raise and lower the first lift arm assembly,second lift arm assembly, and the top link; and (e) wherein the vehiclefurther includes a plurality of compartments for storage of the firstand second lift arm assemblies and the top link in the second portion ofthe frame.